Dry fork?

Discussion in 'Trials' started by broncobowsher, Jul 22, 2018.

  1. broncobowsher

    broncobowsher Long timer

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    So I am getting around to some much delayed maintenance on my 2012 Sherco 2.9. Wasn't happy with the dealers idea of fork maintenance (when it starts leaking, bring it in and we will rebuild it). Been looking for fill levels for the forks. What little I have done involved measuring the oil level from the top of the tube with the fork collapsed and the spring removed. I have never found said level for this bike. Finally it dawned on me that since they are not leaking yet, just measure the level and refill to the same. Don't ask how many years it took to think of that idea.

    So today I have the A/C cranked in the garage and the bike pulled out of its hidey hole. Pulled the left fork off and pulled the cap off the top. Set the spring aside, wiping a touch of oil residue off of it. I don't see oil!? Got me a handy red party cup and poured the oil out. Got a cap full of nasty looking oil. Cycled the fork, left it upside down and got some lunch. Still just a couple of CCs of oil total. Just enough to cover the bottom of the cup. I put some fresh oil in (random amount, couple of glugs) and cycled the fork. That made a huge difference on rebound at full compression. Cycled everything through many times and dumped that oil. Got out about what I put in. This wasn't intended as anything other then a quick flush of the nasty residue that was in the fork. So now I am wondering, was this built wrong and I have been riding it this way for 6 years? I have had people comment that they like the way the suspension feels, including asking Ryan Young to take it for a quick test spin at the world round last year where I got the comment back that it feels better then most of the bikes running the event.

    So I look for some manual on what it should be. The bike is an early 2012, I have a copy of the 2011 owner's manual. In the specs I see "Capacidad botella (google says that is Bottle Capacity)" and the values of "115 left / 55 right". The manual's translation simply states it as "cylinder capacity" but is void of units. The next line is "oil type" and the spec is "SAE 5" so I am pretty sure I am looking at the front forks. And I have a new bottle of 5W fork oil to go in.

    I am just at a loss for an empty fork. I've had the bike since new. Never had a leak (that is why I am doing maintenance, to try and prevent a leak). I'm not sure if I should just put a little clean oil back in and run with it empty? Or should I actually fill it, and if so how much? is the 115 the CC of oil to put in or the distance down the oil level should be in mm?

    So if you can't tell I am at a total loss of what I should do.

    No, I have not taken the Right fork apart yet. I only want so many parts scattered around the shop. I am at the stop, research, beg for help before I go too far stage right now.
    #1
  2. 10K

    10K Trail Runner

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  3. broncobowsher

    broncobowsher Long timer

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    Thank you. Looks like the numbers in the manual match the air gap measurement and are not volumes.
    Time for some oil I guess. I wonder why everything was so happy with no oil in it?
    #3
  4. 10K

    10K Trail Runner

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    It may have been happy before, it will be ecstatic now! :thumb
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  5. Huzband

    Huzband Team Dirt

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    Yeah, but now his seals will leak.













    :hide
    #5
  6. broncobowsher

    broncobowsher Long timer

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    If the seals start to leak I'll just drain the oil out.

    This is what I got out of the left fork (in a red party cup for reference)
    IMG_20180722_143519489.jpg

    The right folk was about 12mm low. I refilled it to the 55mm mark. Jumping up and down on the bike in the garage it feel fine. Too hot to ride. See what happens when I take it to the mountains in 2 weeks.
    #6
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  7. 10K

    10K Trail Runner

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    Come up to Alto next weekend for some peg time.
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  8. heffergm

    heffergm Long timer

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    I don't even see how that's possible if these are indeed Tech forks you've got. They take a decent amount of oil, and for it all to disappear without you noticing seems unlikely.
    #8
  9. motomofo

    motomofo Been here awhile

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    When the fork begins to leak, clean the fork seal. 99% of the time, there’s absolutely no reason to disassemble a fork due to a leaky fork seal.

    Attached Files:

    #9
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  10. Nobade

    Nobade Been here awhile

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    Hey that's a neat seal cleaner. Who makes it?
    #10
  11. broncobowsher

    broncobowsher Long timer

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    Tech forks. Never leaked a drop. Owned the bike since new. I got the bike with them this way. Never checked them until this weekend.
    Oh, the right fork was just a little down or else I just overfilled it a little.

    As for Alto pit this weekend. It looks like I can pull that off. Been a long time since I was up there not for an event. It is only an hour further away then Wildcat. Still Sunday mornings? What time are people getting up there time of year?
    #11
  12. motomofo

    motomofo Been here awhile

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    That’s the Risk Racing Seal Doctor. Comes in two sizes, the smaller one works on trials bikes. Everyone should have one in their tool box (plus the larger one, if you also ride MX/enduro bikes). Available on Amazon.
    #12
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  13. Nobade

    Nobade Been here awhile

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    Cool, thanks! I'll get them. Looks better than the tearoff lens I use now.
    #13
  14. 10K

    10K Trail Runner

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    There were 6 yesterday at 8 am. It's nice to ride around and tackle some of the previous novice sections.
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  15. broncobowsher

    broncobowsher Long timer

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    Sounds good. I'll be there.
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  16. broncobowsher

    broncobowsher Long timer

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    After 3 days of riding I can tell a little difference. Coming down hard on the front end would result in a hard bottoming out. Now I don't get the hard bottoming out. The reduced air space makes for a more progressive spring rate at the top of the compression. Makes sense. I don't think anyone who rode it ever beat on it hard enough to bottom out the forks.
    #16